Shutter speed

First, this recently viral helicopter take off, with a near perfect shutter speed to rotor blades ratio:

Which reminded me of the people that played with pouring water and speaker frequencies a while back:

And then, to take it one step further and back to the skies, with consideration of how a rolling shutter works:

That last one still bends my mind slightly, while trying to visualise exactly what’s happening. Also, I’m glad we don’t have faster ‘shutter speeds’ in our eyes. Sights like this in real life would be pretty disturbing I expect. Not to mention how much bigger our eye apertures would need to be!